I have a Black Copper Marans pullet that I purchased as a 10 week old. She began laying 3 months ago and is currently 9 months old. She laid about 4-5 eggs a week before discontinuing production 2.5 weeks ago. We are located in the Northeast, it's been 40-50 by day and 25-34 at night. Just a bit of history... Yesterday she was found roosting in the nest box, which is abnormal for her. I removed her and placed her on the roost, and noticed she was a bit lighter then usual and she kept her feet tucked as I moved her. Today she briefly came out of the coop, when I came back 4 hours later from work she was back in the nest box and remained there all afternoon. She's lethargic, but picked some of the sunflower seeds that I tried enticing her with. Is seemingly off her normal feed completely, is a bit wobbly to stand, a tiny bit wobbly in her head/neck and does not stand completely when walking, she will walk very little- but has managed getting up into the nest box twice. She's not rocking back on her hocks or ruffling her feathers like a typical sick bird. Clear eyes, clear nose, no breathing issues or coughing, shiney feathers, the loss in weight isn't much, clear vent. Poop had a clear liquid mucus, some green particles, and little bit of tannish color, and not much of it. I've offered vitamin/electrolyte/probiotic mix water that I syringe every two hours, shelled unsalted sunflower seed with her normal feed, I've made her a mash of it also. She's caged alone now. My other birds are well so far. Only change has been their feed, it went from 18% starter/grower to 21% chick starter/grower (I have a mixed age flock) and it's a different brand, both organic no medications etc. I mixed the two together. Always a hopper of oyster shell and a hopper of granite. Not much has been given for scraps in the last couple weeks, they are free range with free choice feed/water. Suggestions anyone??!! Thanks in advance!!!